Paul has a medical degree from Duke University. However, he was trained as an ophthalmologist and not a psychiatrist. Paranoid schizophrenia is a mental disorder.

“I looked at some of the writings of this young man, and from a medical point of view there’s a lot to suggest paranoid schizophrenia and a really sick individual,” Paul said on “Fox News Sunday.”

This is not the first time a Senate Republican has offered an off-the-cuff diagnosis in a politically charged climate. In 2005, then-Senate Majority Leader Bill Frist (Tenn.) weighed in on the case of Terri Schiavo, a Florida woman in a vegetative state whose family was battling over whether to end her life. Her feeding tube was removed later that year, and she died.

Frist, a heart and lung transplant surgeon, said that video showed she was not in a persistent vegetative state, as her doctors had ruled.

“I question it based on a review of the video footage, which I spent an hour or so looking at last night in my office. ... She certainly seems to respond to visual stimuli,” Frist said in a floor speech.